Variable speed transmission



iApril 1-5, 1941. w. PQ scHMlaTER 2,238,801,

l V-VARIABLE SPEE TRANSMISSION Filed July 14, 1957 mwwvmw a. m N 2. RIl. IN

nu mw Qw ATTORNEY.

Patented Apr. 15, 1941 VARIABLE 'SPEED TEASMISSION Walter P. Schmitten',Milwaukee, Wis., assignor to The Falk Corporation, Milwaukee, Wis., acorporation of Wisconsin Application July 14, 1937,- Serial No. 153.607

' 1s claims. (ci. 'x4-281) This invention relates tovariable speedtransmissions of the type involving a plurality of 4taperedlinclinedplanet rollers controlled by a traction ring arranged for` movementlengthwise of the rollers.

A variable speed transmission of this type is disclosed in the copendingapplication of Alfred G. Bade, Serial No. 121,110, filed January 18,1937, in which the carrier for the rollers is movable lengthwise of andwith respectto the rollers in a manner to develop contact pressuresbetween the rollers and ring.

A general aim of the present invention is to further improve theconstruction and operation of transmissions of. this type.

A more specic object is to incorporate a load equalizing system designedto coact with the rollers in a manner to insure that each will carry itsshare of the total torque load. l

Another object is to provide simple and improved means for` ilxing therollers against lengthwise movement.

Anotherobject is to combine an electric motor with a transmission of thecharacter described in a manner to provide a self-contained, variablespeed, power unit.

Other more specific objects and advantageswill appear, expressed orimplied, from the following description of an illustrative embodiment ofthe present invention. l

In the accompanying drawing:

posite the end to which the motor I is attached.

In this instance the driven shaft I8 is jouri nalled in `appropriateaxially spaced bearings I9 Figure l is a vertical, longitudinal,sectional` view of a variable speed power unit constructed.' inaccordance with the present invention.

Figs. 2, 3 and 4 are fragmentary sectional views illustratingalternative forms. of variousl hereinabove identified.`

The transmission shown in Fig. 1 includes a plurality of relativelyinclined tapered planet rollers I2, mounted to rotate with and withrespect to ua. rotary carrier I3, and controlled by an encircling ringi4 which contacts all of the rollers` and which is movable'lengthwise ofthe latter to regulate their motion. Each roller carries a planet pinionI5 ilxed thereto, the several pinions I5 meshing with an encircling ringgear Il mounted for rotation with a carrier disk I1 ilxed tothe innerend of a driven'shaft I8 pro-v jecting through'that end of the housingII opin the housing end and serves to support one end of the rollercarrier I3, the latter having an integral stub shaft journaled in a.bearing 2| fixed in the hub` portion 22 of the gear carrier I1. 'I'heother end of the roller carrier I3 is supported by a similar shaft 23projecting axially therefrom and journalled in a bearing 24 xed in acage 25 removably mounted in the housing end. The bearings 2| and 24 areof an axially adjustable type to permit iree Aaxial movement of thecarrier I3.

Each roller I2 is supported in opposite ends of the carrier by similaraxiallyadjustable bearings 26 so as not to interfere with the freedom ofmovement of the carrier I3 axially, the rollers being retained againstlengthwise movement preferably by means which will now be described.

AIn this instancevthe` hub 22 of the gear carrier is provided with anoutwardly projecting continuous ring or shoulder 21 which bears againstan end face of each pinion I5 to hold the several rollers againstmovement toward the left; and the periphery of the gear carrier isprovided with a similar but inwardly projecting ring or shoulder 23which bears against collars 29, each fixedvv toone of the rollers in amanner to hold thel several rollers against movement toward the right,it being understood that the carrier II is hollow and provides anannular chamber 30 open on that side toward the rollers to accommodatethe4 collars 2! and their mountings. For purposes of4 assembly, thecarrier I1 is also` provided with side openings 3| through which accessmay be had to the collars 28.

With the rollers l2 thus xed against lengthwise movement and relativelyinclined in the manner shown, any thrust against the roller carrier I3`urging it toward' the right reacts through the bearings 26 to force therollers outwardly against the ring I4 in aI manner to increase thecontact pressures between the rollers and ring. In the transmissionshown in Figure I, the carrier I3 is urged toward the right by 'meansenergized by the torque load on the ring fixed to one end ofthe'shaft32, meshes with a segmental gear 38 having a hub 39 disposed .within the-cage 25 and rotatably mounted on a thrust-sustainingball bearing 43ilxed on the shaft 23. The hub 39 carries a cam ring 42, rotatabletherewith, which coacts with a` nonrotatable cam ring 43 and a vset ofinterposed ballsl 44 to exert an axial thrust upon'the bearing 40 andshaft 23 in response to rotation ofthe hub 33. In this instance, thereactive thrust imposed on the cam ring 43 is sustained by a centeringring 45 normally seated against the end head 45 of the cage 525 andyieldably 'urged by a plurality of springs 4 I to maintain Aan :Initialpressure between the balls 44 and cam rings.

'I'he arrangement is such that any'torque load imposed upon .the ring I4by the rollers I2 is transmitted through the gear teeth 36 and 35 to therock shaft32, and thence through the gears 31 and 38 to the cam ring 4E,tending to rotate the latter and thereby imposing an end thrust on theshaft 23 in a direction to urge the roller carrier I3 toward the right.As above pointed out, the roller carrier I3, thus urged, reacts on therollers I2 to force them against the ring i4 and thereby develop contactpressures between the rollers and ring ofy a magnitude proportional to ythe torque load on the transmission.

I It will be noted that the use of gears 35, 35, 31 and 38 in the.manner described affords a greater range of motion than does the systemof levers employed in theapplication hereinabove identified and at thesame time maintains a constant relation between the torque load on thecontrol ring I4 and the torque load on the cam ring 42 in all angularpositions of the rock shaft 32.

Since the contact pressures between the rollersA l I2 and ring I4A areproportional to the thrust imposed` on the carrier I3 by the cam ring82, and since this thrust is proportional to the torque contactpressures of predetermined magnitude between the rollers IZ- and ring Itby means such. v'for instance, as that illustrated in Fig. 3. In thisinstance a heavy compression spring 4B is shown, interposed between aanged nut 49, thread-ed on' `the end of the, cage 25', and a,thrustsustaining bearing 40' on the carrier shaft 23, so that the carrier isyieldably urged toward the right rby the thrust of the spring 48 whichmay be regulated by adjustment of the nut 49.

The roller carrier I3 in the device shown is directly driven' from themotor I0 preferably through speed reduction gearing, tor avoidobjectionable high carrier and roller speeds, to permit freedom of axialmovement of the carrier I3, and to aiford ready removal of the motor.ing shown includes. an internal gear 55, formed within a drum Iremovably fixed to the carrier shaft 23, `and meshing with a pinion 52removablyflxed to the end of the motor shaft 53, and

. arrangement which aords the desired redllcvn l aaaasoi in carrierspeed with a minimum offset relation between the axes of the shafts 23and 53.

In this instance the motor shaft 53 is journalled in abearing 54 seatedin an end head 55 detaehably fixed to the cage 25, and the motor housingis detachably mounted on the end of thev housing il through anappropriate adapter 5S. It will be noted that the arrangement shownpermits ready withdrawal of the motor I0, with its shaft 53 and pinion52, from the housing-i i, end I head 5d, and gear 5U. l The gear 5t andcoacting pinion 52 are preferably of the single helical type with thehelix angle of .the teeth in' such direction that the transmitted torquetends to further increase the axial thrust on the roller carrier I3, tothereby further increase the contact pressures between .66 removablyfixed tothe periphery of the gear the rollers I2 and ring I4` as thedriving torque increases, the helix angle also being such as to opposethe thrust resulting from the reaction of the single helical pinions I5and gear I5. However, straight spur gears may be employedl as in dicatedat as' and 52' in Fig. 3.

Provision is made-in the device shown for effecting a substantiallyequal distribution of the torque load among the several rollers I2, soas to insure l Ithat each carries its proportionate share oi the totalload, and thereby make it possible to transmit amaximum load Withoutslippage between any of the rollers I2 and the ring i4. To accomplishthis, correction or compensationy must be made for slight differences inthe planetary movements of the rollers, due, for in,

stance, to slight differences in the radii of the several rollers attheir respective points of contact with the ring I4.

4In the machine shown, this is accomplished by so mounting the gear I6as to permit free radial movement of the latter relative to the pinionsIii.

For this purpose the gear I6, in the device of Fig.

1, is connected in driving relation with its carrier I'l solely througha single fulcrum pin 5l' anchored in the carrier and projecting looselythrough a radial slot 58 formed in the body of the gear, so that thegear is free to swing about the .pin 51 andto shiftalonga diameterthrough the pin. An inturned flange 59 carried by a ring carrier Ilcoacts with' the carrier toy loosely retain the gear against tilting outof its properv plane.

yThe arrangement is such that if the torque load on any of the rollersI2 is materially in excess of the load on the others, the resultingincreased tooth pressure between its pinion I5 and gear I6 4will forcethe gear It radially outward therefrom vto relieve the pressure and tcthereby so vary the Iaction between that pinion and gear as tocompensate for the abnormal planetary action of the roller whicheausedthat abnormal load. In other words the gear IS is' radially free toassume a position which will equalize the tooth pressures between theseveral pinions i5, thereby not only l In this instance the gear. andconnector il are both loosely conilned by a ilanged ring 6I' iixed tothe carrier. y

In Fig. 2 is illustrated another variation of the invention wherein anexternal gear I6 has been substituted for the corresponding internalgear shown in Fig. 1. In this instance the gear i6',

engaging the several planet pinions I5 of the rollers I2, is iloatablymounted in a similar manner upon a carrier I1 iixed'to the` driven shafti8,4 a single fulcrum pin 51', engaged in a radial slot 58' in the gear,constituting the sole driving connection between the gear and carrieril'. The gear i 6' is thus free to shift radially in any direc-- tion soas to equalize'the pressures between it A collar 28 on the driven shaftI8- coacts with collars 29 onthe rollers I2 to sustain the rollersagainst lengthwise movement with the carrier i8.

Cil

ratio of the transmission, and load transmitting gearing including a setof gears relatively adjustable in response to the torque loads on saidrollers to substantially equalize said loads.

4. A variable speed transmission comprising a rotor, a plurality ofrelatively inclined tapered planet rollers rotatable with and withrespect to said rotor, a ring engaging said rollers and moveablelengthwise thereof to regulate `the speed ratio of the transmission, `aplurality of planet pinions each connected in driving relation with oneof saidrollers, and a load transmitting gear coacting with said pinionsand radially moveable inu response to the torque loads on said pinionsto substantially equalize the loads on said rollers.

5. A variable speed transmission comprising a rotor, a plurality oirelatively inclined tapered planet rollers rotatable with and withrespect to said rotor, a ring in pressure 'contact with said rollers andmoveable lengthwise thereof to regu# 'relation with one of said rollers,and a load transy mitting gear engaged with said pinions, said ringbeing'radially moveable to substantially equalize the contact pressuresbetween it and said rollers,

`In the transmission shown in Fig. l, the conwhich is loosely engagedwith the ring, and' which is threaded upon an actuating and controlscrew E5 journalled in appropriate brackets in the top of the housing Il. s, The screw 65, and consequent- 1y the nut 68, are actuated andcontrolled by appropriate means, such as a hand wheel 66, mountedexternally of the housing Il and connected to the screw* shaft 65through appropriate gear-A ing 51.

For purposes of cooling, the housing is provided with inner walls 68spaced from the outer wall and coasting therewith to form. `airconducting channels 69 which extend the full length of the housing. Airentering ports 10 at the forward' end of the housing is induced to iiowthrough the channels 69`by the action of a centrifugal fan 'gli carriedby and rotating with the motor shaft $3. This cooling vair* exhauststhrough appropriate openings 'l2 in the adapter 56.

Various changes may be made in any of the embodiments of the inventionhereinabove specifically described without departing from or sacriclngthe advantages of the invention as delined in the appended claims.

Irclaim':

1. A variable speed transmission comprising a rotor, a plurality ofrelatively inclined tapered planet rollers rotatable with and withrespect'to said rotor, a ring engaging said rollers and mov.- ablelengthwise thereof to regulate the speed ratio of the transmission, andmeans responsive to the torque loads on said rollers for equalizlng saidloads.

2. A variable speed transmission comprising a rotor, a plurality ofrelatively inclined tapered planet rollers rotatable with and withrespect to said rotor, a ring engaging said rollers and movl ablelengthwise thereof to regulate the speed and said gear being radiallymoveable to substantially equalize the torque loads on said rollers.

. 6. In a device of the character described the combination of a. rotor,a plurality of planet members rotatable with and with respect to saidrotor, means engaging said members to centred the planetary actionthereof, a plurality of planet pinions each connected in drivingrelation with one oi said members, and a torque 'transmitting gearengaged with said pinlons and freely adjustabie relative thereto inresponse to the torque loads on said planet gears to substantiallyequalize the torque loads lensad members. l

7. In a device 'oi the character described, the combination of a rotor9a plurality of planet members rotatable with and with respect to saidrotor, means engaging said members to control the planetary actionthereof, a plurality of planet gears each connected in driving relationwith one of said members, and a load transmitting ring gear encirclingand engaging said planet gears and radially moveabie to substantiallyequalize the torque loads on said members.

8. In a device of the character described the combination of a rotor, aplurality oi' planet members rotatable with and with respect to said Yrotor, means .engaging said members to control the planetary actionthereof, a. plurality of planet gears each connected in driving relationwith one o! said members, and a load transmitting sun gear engaging saidplanet gears and radially moveable to substantially equalize the torque'loads on said members.

9. In a device of the y character described the combination oi' a rotor;a plurality of planet members rotatable with and with respect to said 1`rotor, means engaging said members to control the planetary actionthereof, load transmitting gearing automatically adjustable in responseto the torque loads on said members to substantially 'equalize thoseloads, and means operable independently of said gearing for driving saidrotor.

l0. In a device oi' the character described, 4the combination of an.axially movable roter, a plurality of planet members mounted in androtatable with and withv respect to ysaid rotor, means engagedfwith saidmembersto control their'planetary action, means responsive to axialmovement of said rotor for developing' contact pressures between saidmembers. and saidV first named means, a driver for said rotor, and anaxially Ayieldable driving connection between said Y driver and rotorpermitting axial movement of said rotor relative to said driver. f

11. In a ldevice of the character described, the combination of anaxially movable rotor, a plurality of planet members rotatable with andwithrespect to said rotor, means engaged with said to said driver. y

f 12. In a device of the character described, the combination of anaxially movable rotor, a plurality of planet members rotatable withIVand .with respect to'said'rotor, means engaged with said members forcontrolling their planetary action, means responsive to 'axial movementof said rotor for developing contact pressures between said members andsaid rst named means, a ldrive shaft, and means including a pair of in-`termeshing single-helical gears through which said rotor is driven fromsaid shaft, said gears reacting to 'impose an axial thrust on saidrotor.

13. In a device of the character described, the combination of anaxially movable rotor, a plurality of planet members rotatable with andwith respect to said rotor, means engaged with said members to controlthe planetary action thereof, means responsive to axial movement of saidrotor for inducing contact pressures between said members and said firstnamed means, a'drive shaft, and means responsive to the torque load onsaid drive shaft for imposing a pressure inducing axial thrust on saidrotor.

14. In a variable speed transmission, the combination of a rotor, apluralityof relatively inclined tapered planet rollers rotatable withand with respect to said rotor, said rollers and rotor being mounted forrelative lengthwise movement, a driven single-helical gear.single-helical planet gears connected with said rollers respec ltivelyand reacting on said driven gear to urge said rollers lengthwise in onedirection, and driving means for said rotor including single-helicalgears reacting to urge said rotor axially in an in and rotatable withand with respect to said rotor, a control memberencircling andcontacting said rollers, elastic biasing means for urging said rotoraxially in one direction, and means responsive tothe axial thrust thusimposed on said rotor for forcing said rollers against said member.

16. In a variable speed transmission the combination of a rotor, aplurality of relatively inclined tapered planet rollers mounted in and.rotatable with and with respect to said rotor,

driven means including a single helical driven gear and single helicalpinions connected with said rollers respectively and reacting with saiddriven gear to impose an axial thrust on said rollers. Y

17. In a variable speed transmission the combination of an axiallymoveable rotor, a plural- ,ity of relatively inclined tapered planetrollers rotatable with and with respect to said rotor, means encirclingand4 contacting said rollers and moveable lengthwise thereof to regulatetheir motion, a drivenl shaft responsive to the planforming shoulderscoacting with said rst named shoulders to control the lengthwiseposition of said rollers, and means responsive to axial movement of saidrotor for forcing said rollers against said encircling means.

18. In a variable speedY transmission the combination of an axiallymoveable rotor, a plurality of relatively` inclined tapered planetrollers rotatable with and with respect to said rotor, means encirclingand contacting said rollers and moveable lengthwise'thereof to regulatetheir motion, a driven shaft responsive to the planetary motion of saidrollers, a'member carried by said shaft and having a peripheralshoulder, means carriedby each of said rollers forming a shouldercoacting-with said ilrst named shoulder to restrain said rollers againstendwise movement with said rotor, and means responsive to axial movementof said rotor for forcing said rollers against said encircling means.

WALTER P. scHMrrrEa.

